In recent years, a user interface that uses a sound has been getting popular. The user interface that uses a sound is used to make a phone call or search information, in a mobile phone (a device such as a smartphone) for example.
However, when the user interface is used in a condition with a lot of noise, a sound generated by a user cannot be properly analyzed due to the noise and a wrong process may be executed. Patent Document 1 proposes to emphasize a sound by a fixed beamformer, emphasize a noise by a block matrix unit, and perform generalized side lobe canceling. Further, Patent Document 1 proposes to switch a coefficient of the fixed beamformer by a beamformer switching unit and perform the switching by switching two filters between a case with a sound and a case without a sound.